Process for separating meat from bones



April 1970 c. A. ALLDRED, JR ET AL Original Filed Oct. 31, 1967 PROCESSFOR SEPARATING MEAT FROM BONES 4 Sheets-Sheet 1 INVENTOS CYRUS 4.4112950, JR

06348 J. CONRAD A ril 21, I970 c. A. ALLDRED, JR., 07,

PROCESS FOR SEPARATING MEAT FROM BONES Original Filed Oct. 31, 1967 .4Sheets-Sheet 2 D/REC 770/V Ilia 1 .78 1/ 5 [4 /ssc. AP/Pax) A ril 21,1970 c. A. ALLDRED, JR. ET 3,507,337

PROCESS FOR SEFARATING MEAT FROMBONES Original Filed Oct. 51, 19","

.4 Sheets-Sheet 5 I I I l l l I 1 1 l T l April 21, 1970 c. A. ALLDRED,JR.. ETA!- PROCESS FOR SEPARATING MEAT FROM BONES Original Filed Oct.31, 1967 4 Sheets-Sheet 4 United States Patent Int. Cl. B07b 13/00 US.Cl. 2092 7 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus aredisclosed for effectively sorting or separating meat from conglomeratemasses of already disunited meat and bone. The present inventionexploits the variations in the characteristics of differing substances;more specifically, the different adhesive characteristics of meat andbone so that these two may be efficiently separated. The force of whatis termed adhesivefriction is deployed in connection with certain otherforces, namely centrifugal force, gravity and certain combinationsthereof, to the end that the stickiness or adhesive properties of themeat will enable the separation of the meat from bony substances in anefficient and extremely simple manner. The present disclosure describestwo basic configurations employing the above-noted principle. These area drum and an impact configuration or embodiment.

This is a continuation of application Ser. No. 679,498 filed Oct. 31,1967, now abandoned.

BACKGROUND, OBJECTS, AND SUMMARY OF THE INVENTION It has been recognizedas a highly desirable goal in the preparation of certain meat productsthat the meat be efficiently but gently disunited from the bones towhich it.

normally adheres. The need for gentle separation of meat from bone isespecially acute in the preparation of a poultry meat product such aschicken, which is to be canned or frozen, or otherwise treated. Ifgentle techniques are not employed but in contrast, bony pieces, such asthe wings, back and necks, are subjected to an impact device, such as ahammer mill, there is a tendency to crush the meat and also, to shatterthe bones with the result that tiny bone fragments may be present in thefinal food product.

The incentive to recover the meat from the aforenoted bony pieces ofchicken derives from the economies that can be effected by increasingthe yield from the meat processing operations. Normally such bony pieceswould be discarded as economically infeasible to bother with. However,if automatic separating techniques can be applied the prohibitive laborcosts associated with the manual removal of the meat would beeliminated.

One of the basic difiiculties in the handling of chicken meat is thatbecause of the small sized bones it is not a simple matter to remove themeat and immediately separate the meat from the small bones. In otherwords, in the processing of chicken meat and the like it is inevitablethat, in the attainment of the disuniting of the meat and "ice bones,there will result an output consisting of a conglomerate mass of meatand bones, and further steps must be performed to separate thesecomponents.

An effective technique and apparatus for gently disuniting the meat fromsuch bony pieces as chicken wings and the like has already beendescribed in copending application Ser. No. 603,484, filed Dec. 21,1966, and assigned to the assignee of the present application. Thepresent invention is related to the invention disclosed in the copendingapplication by reason of the fact that the product resulting from thedisuniting apparatus described in the copending application consists ofa conglomerate mass of disunited meat and bone. Although the initialdisconnection or disuniting of the components is performed by suchapparatus, it remains to separate completely these components so thatthe bones may be discarded. In the prior art it has become conventionalto deal with the problems described above, that is, to isolate the meatfrom the bones as they are presented in a conglomerate mass by utilizinga brine tank for example. Another technique is what is known as ahydrodynamic technique; also, certain screening methods have beendeveloped for this purpose.

It is a fundamental object therefore of the present invention toefficiently sort out materials of different characteristics fromconglomerate masses of these materials.

Another object is to provide a simple technique for the separation ofmeat from bones when it is required to separate conglomerate masses ofthese materials.

Another basic object is to reduce both the initial costs and themaintenance costs of such a separation operation.

The present invention in its broadest aspect relates to a method and toapparatus for sorting or separating and recovering the meat fromconglomerate masses of disunited meat and bone. This is accomplished bythe utilization of what is termed adhesive-friction. The termadhesive-friction is used to refer to a combination of friction, filmand associated surface phenomena. In order to obtain the properadhesive-friction characteristic so as to achieve the desired result ofeffective separation, it is necessary in some cases to add a fluid as amechanical catalyst. This aspect will be discussed hereinafter inconnection with the several embodiments of the present invention.

In its broadest aspect, then, the present invention is based on therecognition that one can uniquely capitalize on the fact that meat hasnatural sticky or adhesive properties, and thereby can cause the meat tobe affected differently from the bony substances which are to bediscarded.

'In accordance with more specific features of the present invention, infulfillment of the previously stated objects, the adhesive-frictionprinciple is embodied in two basic configurations which will bedescribed hereinafter. Common to both of these configurations is thenotion of rotating the composite or conglomerate mass of disunited meatand bones so as to impart a predetermined velocity thereto so that, onthe one hand, the meat, because of its adhesive properties, willinitially cling or adhere to a surface with which it comes in contact.On the other hand, the bones, when rotated in like manner and caused tocome into contact with the same surface, will not so cling so that theyare readily separated from the meat which has adhered to said surface.

The first embodiment for implementing the principle stated above is adevice which consists essentially of a ilrum rotatable about an axiswhich is slightly inclined from the horizontal. The disunited carcassmembers, such is disunited chicken wings or the like, are fed into thehigher end of the drum. An adhesive film of natural luices, or a filmthat is formed by a combination of the natural juices with a catalyticfluid or even water, is such that the meat sticks to the drum and isrotated upwardly Jntil it is caused to fall into a collecting conveyorand then carried by a conveyor belt or the like to the next processingstation. Because of the lack of adhesion of the bones, they do notadhere in the aforenoted manner and are discharged at the lower end ofthe inclined drum.

An alternative embodiment, which is known as an impact configuration,takes the form of a device consisting of a rough disk which is rotatedon a vertical axis. The disk functions to throw the composite orconglomerate masses of meat and bone against a shield. The bones bouncefrom the shield over a separating wall of a funnellike member. Incontrast, their natural adhesive-friction qualities results inabsorption of the kinetic energy from the meat particles.

The foregoing and other objects, features and advan- :ages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS.

FIG. 1 is a perspective view of the first embodiment of the apparatus inaccordance with the present invention. This will be denominated the drumembodiment.

FIG. 2 is a longitudinal section view of the apparatus of FIG. 1. f

FIG. 3 is a view looking from the feed end of the drum of FIG. 1.

FIG. 4 is a graph depicting the movement of the conveyor pan. 1

FIG. 5 is a view looking from the fee-d end of the drum of FIG. 1 andillustrating a modification involving a par- :icle acceleration aid.

FIG. 6 is the same view as FIG. 3, i.e. looking from the feed end of thedrum of FIG. 1, but illustrating a different modification.

FIG. 7 is the same end view, but illustrating yet another modification.

FIG. 8 is a schematic diagram depicting the processing of a foodproduct.

FIG. 9 is a vertical sectional view taken along the line 99 in FIG. 8. f

FIG. 10 is a fragmentary view illustrating a modification to the drumembodiment.

FIG. 11 is a vertical sectional view of the alternative or diskembodiment for the apparatus of the present invention. ,1

FIG. 12 is a perspective view, partly broken away, illustrating amodification of the disk embodiment of FIG. 11.

DESCRIPTION OF PREFERRED EMBODIMENTS First embodiment Referring now tothe moment to FIGS. l3, there is illustrated in the several views thefirst embodiment of the basic apparatus of the present invention. Thisembodiment is denominated the drum embodiment because the apparatusessentially comprises a drum 10 which is adapted for rotation asindicated by the arrow in FIG. 1. Typical means (not illustrated) areused to produce the required rotation of the drum .10. The drum 10 iscarried by a base member 12 and is adapted for rotation on a variableaxis by virtue of a frame 14 which is pivotally connected at one end tothe base 12. An adjustable bracket at the other end of frame 14 allowsfor shifting the axis of rotation of the drum 10 from the horizontal.That is to say, the drum 10 is adapted for varying inclination, and,preferably, its delivery end 10a is established below the horizontalwhile its feed end or input end 10b is established above the horizontal.The drum .10 is guided in its rotational movement by the pairs ofrollers 14a and 14b which are engaged, respectively, by the tracks orrunners 16a and 16b, shown encircling the drum 10.

Disposed within the drum 10 is a longitudinally extending conveyor pan18 which is arranged to be driven in a special way for a purpose to beexplained. Also situated closely adjacent the inside surface of the drum10, at the uppermost point in the rotation thereof, is a scraping device20 which is illustrated as being in two sections for the purpose ofadjusting the closeness of the edge of the scraping device to the insidesurface of the drum 10. In other words, the portion of the scraper 20which is shown as being closer to the inside surface can be shifted tomaintain yieldable contact with the inside surface. The scraping device20 is suitably supported by means, not shown, to achieve its function. Apipe 22 extends longitudinally through the drum below the conveyor pan18 and a typical source of Water or fluid is supplied by this pipe 22 tothe interior of the drum through suitable nozzles or apertures.

At the lower or delivery end 10a of the drum, the conveyor pan 18extends over the conveyor belt 24 which is adapted to carry theout-flowing meat to the next processing station.

In the operation of the drum apparatus of FIG. 1, a convenient feedhopper 26, shown in phantom outline in FIG. 2, may be disposed so that aconglomerate mass of disunited poultry meat and bone may be fed into theinterior of the drum 10. It will be understood of course that anyconvenient means may be adapted to feed the disunited material in thismanner. As noted before, the apparatus now being described is designedto be employed at the output of the disuniter apparatus described incopending application Ser. No. 603,484. In such arrangement, thedisuniter apparatus is preferably mounted on caster wheels and thus canbe very easily moved away from the drum 10 in order that both pieces ofapparatus may be separately cleaned. Also, with such a portablearrangement, the need for a special conveyor device to transportdisunited carcasses from the disuniter apparatus is obviated.

When the composite or conglomerate mass consisting of disunited meat andbone from poultry carcasses is injected into the interior of the drum10, the meat portions adhere to the drum as they strike the bottom andare carried upward as the drum is rotated to the top of the rotationalpath. At this point the average particles of meat, that is, those thatadhere with average binding force to the inner wall of the drum 10 arepulled away by reason of the force of gravity overcoming the totalcombined forces of rotational movement and adhesion. However, in theevent that some of the particles do not fall by dint of gravity, ascraping device 20 is provided. Thence the meat falls onto the collectedtray or pan 18. This operation can be appreciated by referring to theseries of arrows 100.

While the aforedescribed effects occur for the meat portions of thecomposite or conglomerate mass, the bones, since they do not adhere tothe drum, tumble away from the inner surface as indicated by the seriesof arrows 102 and tumble through the drum and are discharged at thelower end into a receptacle 104 located below this delivery end.

It will be manifest to those skilled in the art that the forces ofgravity, centrifugal and adhesive-friction are the dominant factorswhich produce the effective separation of meat and bone as describedherein. It will be understood then that, in essence, centrifugal forceis almost sufficient to counteract gravity to the extent that a particlemay be rotated to the top or near enough to be caught by the conveyorpan. With the addition of adhesive force, the total force is greatenough. In other words, a meat particle is capable of being moved up tothe top of the drum and of contacting the scraper device 20 by reason ofthe fact that the adhesive force, when combined with the centrifugalforce due to the rotation of the drum 10, is sufiicient for thispurpose. As stated before, those meat particles which are initiallyretained by slightly smaller adhesive forces will be overcome by theeffects of gravity and will be pulled from the drum before they reach orcome close to the scraper 20.

It will be appreciated that in the situation of interest here theanalysis of the so-called adhesive-friction phenomena is a complexmatter. It appears from numerous tests that have been conducted thatwhen the drum is rotated slowly, adhesion is the dominant factor in theoperation and when the drum is rotated fast, friction dominates. Duringslow drum rotation all particles stick to the bottom of the drum andwhen they start their rotation upwardly, the previously describedinterplay between adhesive force, centrifugal force and gravity is thedetermining factor in causing the separation. During fast drum rotationthe acceleration of meat particles up to the drum speed is notinstantaneous and may never occur even for the particles separated ontothe conveyor pan 18. The particles separated at the very top of the drumhave been accelerated to a sufficient angular velocity to result inenough centrifugal force to get them to the conveyor pan 18 by a forcewhich may be envisioned as sliding friction.

The adhesive-friction phenomenon that is so effective for poultryseparation, that is, for the separation of conglomerate masses ofdisunited meat and bone, depends to some extent, in certain cases, on afluid film that is utilized. This film may consist of any one or acombination of natural juices, fat, water, etc. As noted before, thespray nozzles formed in pipe 22 are used for the purpose of supplyingthese additional fluids when they are required. When these may berequired is, of course, an empirical matter and may be determined byobservation.

It has been found desirable, when the separation of the meat has beenaccomplished, that is, after the meat particles have been caught orintercepted by the conveyor pan 18, to provide reciprocal movement ofthe pan for most efficient conveying of the meat particles down to theconveyor belt 24. The conveyor pan 18 is driven by an arrangementdenoted by the numeral 28, comprising an arm 30 which at its upper endis connected to pan 18 and is mounted to a bracket 32. A spring 34 isattached at one of its ends to the bracket 32 and at its other end to apoint on the crank arm 30. The operation is such that when themotor-driven cam 36 acts to drive the lower end of the crank arm 30 theresult is that the pan is conveyed in the forward direction; that is, inthe direction toward the location of the conveyor 24. This is done at arelatively slow velocity. However, the cam 36 is so configured that ithas a steep side and when a certain point in its travel is reachedcorresponding to the farthest point of travel for the conveyor pan inthe forward direction, the pan is thereafter snapped or jerked backbecause the steep side of the cam is then encountered and the naturalbias of the spring comes into play to cause the conveyor pan 18 to movesuddenly in the reverse direction.

FIG. 4 shows a chart that was made by a prototype pan conveyor. Thechart records pan position versus time. The chart in effect demonstratestwo methods that are operative in the horizontal conveying due to themovement of the conveyor pan 18 which reciprocates longitudinally, asdiscussed. One of the phenomena that is operative causes movement ofmaterials with very low coefficients of friction when the pan cycle rateis such that the material is essentially sliding all of the time.Referring to FIG. 4, consider a conveyed particle on the conveyor pan18; the force resulting from the coefiicient of sliding frictionaccelerates the particle in the conveyed direction five-ninths of thetime and in the return direction four-ninths of the time.

The other operative phenomenon involves sticky materials havingeffective coeflicients of friction in the order of l-lO. These materialsmay stick to the pan during all of the pan cycle, except the partlabeled B on the one cycle above. During this period the pan deceleratesand accelerates with a force in the order of 10 Gs. Thus, the inertia ofthe conveyed particles supplies a force in the order of 10 GS to breakfree from static friction and move forward.

Referring now to FIGS. 5, 6 and 7, there are illustrated here a numberof added modifications which can be incorporated in the basic apparatusalready described. Thus, there is shown the addition of what are termedpractical acceleration aids. These aids serve a distinct and importantfunction. They continuously start the meat particles that are to beseparated on potential separation revolutions with constant velocitiesfrom a constant angular position. Thus, these acceleration aids have twodistinct advantages: They permit the separation of particles whichdiffer only very slightly in adhesive-friction characteristics andfurther, they permit the separation of particles which produce veryslight force stemming from the adhesive-friction characteristics fromsimilar particles which differ from the first-named particles in thatthey have slightly lower adhesive-friction characteristics.

Referring specifically to FIG. 5, the acceleration aid illustratedtherein consists of a vibrating or belt conveyor 200 which transfers allof the particles to be separated, including the initially fed particles,to an elevated point inside the drum 10 (shown at point A in FIG. 5),such that gravity will impart a radial velocity relative to the drum 10in the direction of drum travel (which is shown as clockwise). In thismodification, the feeding arrangement (not shown) is such that all ofthe meat particles are conveyed directly onto the top run of theconveyor 200 whereby, as already indicated, these particles will bestarted on potential separation revolutions with constant velocitiesfrom a constant angular position. Accordingly, due to the initialvelocity which is imparted to the particles, most of them will reach theconveyor, as indicated by the series of arrows at the top of the drum10. However, due to the slightly different characteristics of variousparticles, some of them -will not reach the conveyor pan 18 but willmove away from the rising side of the drum as indicated by the otherarrows and will fall upon the moving conveyor 200, whence they will berecycled and given another opportunity to reach the conveyor pan 18.

It should be noted that by reversing the direction of the acceleratingaid in FIG. 5, that is, by reversing the direction of the conveyor belt200, particles with large adhesive-friction characteristics will notreach the separating conveyor 18 when the opposite would happen if theywere fed at the bottom of the drum; thus, particles with slightly largeradhesive-friction forces can be separated from those with the originalcharacteristics mentioned above.

Other versions of the acceleration aids for the particles to beseparated are illustrated in FIG. 6 and 7. The accelerating aid in FIG.6 takes the form of a pliable faced cylinder 300 which operates incombination with a baffle 302 so as to cause all of those particleswhich are starting a separating revolution, to pass between it and theinner surface of the drum 10, and thus to acquire drum velocity whichwill permit separation to occur in a similar manner to the separationpreviously described in connection with the accelerating aid shown inFIG. 5

In FIG. 7 the accelerating aid is in the form of a cylindrical paddlewheel 400 which imparts a control velocity to those particles passingbetween the periphery of the paddles and the drum 10. Again, theseparation process is as previously described.

Referring to FIG. 8, there will be appreciated by reference thereto theway in which the separating apparatus of the present invention fits intothe overall scheme of things, that is, in the complete processingoperation consisting of the basic steps of disuniting the meat from thebone of a poultry carcass, separating the conglomerate mass of meat andbone, and thence further processing of the separated meat so as toinsure that tiny bones have been removed. The disuniter apparatusdesignated 500 includes an output chute or shield 510. After thedisuniting operation has been performed, the conglomerate mass of meatand bone is sent down the chute 510 and into the previously-describeddrum separator 10. The meat which has been separated by virtue of thefunction of the drum 10 is conveyed from the conveyor pan 18 onto thetraveling conveyor belt 24 and thence is moved as indicated by thearrows down to the inspection station, at which station there isprovided a tent-like arrangement 550 for the inspection of the meatproducts. Within the tent or booth 550 inspectors are able to detect thepresence of tiny bones remaining in the food product by the use of anultra-violet device 552. Any bones present in the final product willfluoresce under the ultra-violet light produced by the device 552 andsuch bones can then be picked out and discarded in suitable receptacles.The product thus inspected will pass on to the container 560.

FIG. 10 illustrates a modification of the drum separator 10 of thepresent invention. This particular modification is provided forovercoming a problem in the separating operation. The problem occursbecause the disuniter 500 in some instances has a discharge such thatsome of the particles begin the initial separation rotation with apositive angular velocity component while other particles enter with anegative velocity. In order to overcome this difficulty so that theseparating efiiciency will not be impaired an additional scraping device580 is disposed immediately adjacent the feed end of the drum 10, Thescraper device 580, which can, if preferred, be extended into thedisuniter assembly, acts to stop all those particles just entering thedrum and to cause them to fall back and work down the longitudinal axisuntil they are completely clear of the feed area. In other words. theyare sufliciently far from the discharge of the disuniting apparatus.Then they are free to start their separating rotation.

In order to furnish a man skilled in the art with some of the operatingdetails it should be noted that the drum 10 is, as one example,constructed to be 30 inches in diameter by 48 inches long and theseparating drum is rotated for efiicient separation at approximately 16rpm. It was found in tests that were performed with the separating drum10 that the percent meat yield that could be obtained was 37.4%.

ALTERNATIVE EMBODIMENT (FIGURES 11 AND 12 An alternative embodiment thatimplements in a different way the basic principles of the presentinvention is illustrated in FIGS. 11 and 12. This embodiment isconveniently denominated an impact or disk embodiment. As was the casebefore with the first embodiment or drum configuration, the fundamentalprinciple of operation resides in the notion of exploiting thedifference in the adhesive properties between meat and bone in theconglomerate mass of such materials; more particularly, in uniquelycombining several forces including the adhesive force, whereby theforces act upon the conglomerate mass so as to separate the meat fromthe bone.

The apparatus illustrated in FIGS. 11 and 12 comprises a disk 600 whichis suitably journaled for rotation on a vertical axis as indicated bythe arrow 602. Concentric with the disk 600 and spaced below it is afunnel 604 whose top is opened and is immediately disposed below thedisk 600. Beyond the periphery of both the disk 600 and the top of thefunnel 604 is a surrounding shield or barrier 606.

The operation of this form of the apparatus is such that the disk 600rotating on its vertical axis acts to throw the composite orconglomerate mass outwardly from the center of the disk. Of course asdiscussed already, suitable provision is made so that the conglomeratemass can be introduced into the apparatus such that it will fall ontothe central portion of the disk 600. As the conglomerate mass is thrownoutwardly, the meat and bone are thrown against the barrier 606. Thebones rebound from the barrier, that is they bounce over the upper edgeof the funnel 604 and travel down through the funnel to a suitable exitpoint. In contrast to the action of the bones, the meat upon strikingthe barrier 606 tends to cling thereto at least momentarily. This isbecause of the nature of the meat particles whose kinetic energy isabsorbed. The meat particles thereafter due to the action of gravityfall into the space 608 between the barrier 606 and the top portion ofthe funnel 604. This space defined by the shield and the funnelconstitutes a passageway or means for delivering the meat, now separatedfrom the bone, to a chute 610 for conveyance to a suitable collectingpoint.

In some cases, as was also true with the drum embodiment of FIG. 1, itbecomes necessary to provide reciprocating motion for the barrier 606 inorder to cause the adhered meat to slide down and move into the space608 alhough in most cases the force of gravity is sufficient to causethe meat to drop down.

FIG. 2 illustrates a modification to the alternative or disk embodimentof FIG. 11; that is it illustrates a configuration consisting of aplurality of separating disks 600a and 60% spaced from each other on acommon vertical axis, rather than a single disk. With this configurationthe notion is simply to provide a second chance for the meat that hasnot fallen down properly to ts collecting point. In other words, to havethe same essential forces reapplied at the lower disk, that is, disk600b, to perform again the same operation as obtained with the upperdisk 600a.

It will be appreciated that what has been disclosed herein is a methodand apparatus for uniquely exploiting the difference in the adhesivecharacteristics, particularly, of meat and bone so that in conglomeratemasses of these materials the two may be efficiently separated.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to the preferredembodiments, it will be understood that various omissions andsubstitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intention,therefore, to be limited only as indicated by the scope of the followingclaims.

What is claimed is: 1. A process for separating meat from a conglomeratemass of disunited meat and bones comprising the steps of:

feeding a conglomerate mass of disunited meat and bones to a rotatabledevice which is bounded circumferentially by an inner surfaceconstituting a barrier;

rotating said device to impart to the conglomerate mass a predeterminedvelocity such that the meat, because of its inherent adhesiveproperties, initially clings to said inner surface wth sufiicientbinding force to be conveyed upwardly by said surface, and thereafter,due to gravity, moves from said inner surface to a conveyor;

separately conveying the meat as it is received from said inner surface,and discharging the bones from said device.

2. A process as defined in claim 1, in which the step of separatelyconveying the meat includes conveying by a conveyor pan extendinglongitudinally in a direction parallel with the axis of said rotatabledevice.

3. A process as defined in claim 2, further including the step ofreciprocally moving said conveyor pan on its longitudinal axis.

9 10 4. A process as defined in claim 3, further including theReferences Cited step of producing different velocities in the forwardand reverse directions for said conveyor pan. UNITED STATES PATENTS 5. Aprocess as defined in claim 2, further including 1,458,467 6/ 1923 D l athe step of conveying the meat by a conveyor belt as the 1,527,648 5/1927 Johnsonmeat moves from one end of said conveyor pan. 3,042,2087/1962 Holmes- 6. A process as defined in claim 5, further including the3,173,795 3/1965 Toni step of assisting in the removal of the meat fromthe inner surface of said rotatable device by a scraper device. F RANKLUTTER Pnmary Exammer 7. A process as defined in claim 6, furtherincluding 10 U S cl XR the step of spraying the interior of therotatable device with fluid. 171; 146-222; 204-119; 20945, 452

